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MACHINE FOR CLEARING TWIST DRILLS.

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(No Model.) 2 Sheets-Sheet 2. G. R. STETSON.

MAUHINE FOR CLEARING TWIST DRILLS- Patented Jan. 5, 1886.

UNITED STATES PATENT OFFICE.

GEORGE R. STETSON, OF NEW BEDFOBD, MASSACHUSETTS, ASSIGNOR TO HIMSELF AND THE MORSE TWIST DRILL AND MACHINE COMPANY, OF

SAME PLACE.

MACHINE FOR CLEARING TWIST-DRILLS.

SPECIFICATION forming part of Letters Patent No. 333.689, dated January 5, 1886.

Application filed July 11, 1884. Serial No. 137,486. (No model.) i

To all-whom it may concern.-

Be it known that I, GEORGE E. STETSON, of New Bedford, in the county of Iristol and State of Massachusetts, a citizen of the United States, have invented certain new and useful Improvements in Machines for Clearing Twist- Drills, of which the following is aspecification.

My invention relates to machines used in the manufacture of twist-drills to perform the operation known as clearing the drill. This operation consists in gradually reducing the cylindrical faces or lands of the drill in a gradually-increasing degree away from the cuttingedge, the object of such clearing being to prevent the drill from binding when in use.

Letters Patent N 0. 195,963 were granted to me October 9, 1877, for an improved machine for clearing twist drills. That machine is primarily adapted for use in clearing the larger sizes of twist-dri1ls,or those of sufficient crosssection and consequent strength to be cleared by such an apparatus. The machine forming the subject of my present application is priinarily intended for use in clearing the smaller sizes of twistdrills, and is especially constructed with a view to affording a proper support to the drill while under the operation of the clearing-tool. It differs from the machine already patented to me in several particulars, as will be herein more specifically set forth.

My improved machine is represented in the accompanying drawings, in which Figure l is a plan View of the whole machine; Fig.2, a side View ofa portion of the machine with the mechanism which carries the clearing-tool removed, and Fig. 3 an enlarged view in section on the line .90 roof Fig. 1. Figs. 4, 5, and 6 are detail views of the adjustable drill-support, hereinafter described.

My improved machine contains in one structure the following mechanisms, to wit: first, mechanism adapted to be adjusted to suit various sizes of drill, by means of which the drill is held, and through which it may be carried or moved while rotating, so as to present its cylindrical faces to the action of the clearingtool; second, improved mechanism whereby the clearing-tool may be supported and rela tively adjusted to cleardifferent sizes of drill; and, third, improved mechanism for causing the drill while rotating to pass or be carried before the clearing-tool, so that,all portions of the lands of the drill may be suitably acted upon thereby. All these mechanisms are for convenience attached to a common frame or standard, A.

The mechanism for holding and supporting the drill, and through which the drill is moved, consists of the pair of spring closing-jaws B, suitably formed where they engage with the drill to hold it and prevent its being displaced by the action of the clearing-tool, and at the same time to permitit to rotate and be moved longitudinally within them. By means of a screw adjustment (as illustrated at b in Fig.

3) the extent of opening in these jaws may be changed to accommodate various sizes of drill. Thejaws are attached to the main frame A of the machine by a slotted plate and bolt, as shown at O, which affords opportunity for adjusting the position of the jaws toward or away from or along the longest axis of the main frame A 01' the machine. They are also provided with a similar vertical or up-anddown adjustment relatively to the frame 0, by which the height of the jaws may be regulated. This last adjustment is indicated at D, Figs. 1, 2, and 3.

1n the patented machine above referred to the mechanism for holding and supporting the drill, and through which the drill is moved, consists simply ofa rigid bushing of fixed diameter. This construction in the case of a small drill would require as many sizes of bushing as there were sizes of drill to be cleared, and would also make desirable a closeness of fit and accuracy of support not readily obtainable in such a structure. Furthermore, in the patented machine the two points of support of the drillviz., those furnished by the spindle at the heel of the drill and by the bushing already referred toare both on one side of the point at which the clearing-tool bears against the drill.

In my present machine the two points of support are preferably located one on either side of the point at which the clearing-tool strikes the drill, whereby the latter is better prevented from lateral distortion.

The mechanism for carrying and rotating the clearing-tool consists of the pulleyed shaft E, Fig. 1, mounted upon a slotted standard or plate, F, which in turn is carried bya sliding plate, G, arranged to be moved toward or away from the main axis of the frame A by means of the screw and crank H. The sliding of the plate G inward or outward adjusts the distance of the clearing-tool from the drill on which it is to be operated. The plate F is slotted to allow of its adjustment crosswise upon the plate G, and also radially, whereby the face of the clearing-tool may be presented at an angle corresponding with the taper of the drill to be cleared. The clearing-tool is shown at I in Fig. 1, and also indicated in an enlarged view at Fig. 4.

It will be observed that the construction and arrangement of the clearing-tool above described gives me an adjustment of it with respect to the drill which was not attainable in the structure in my'previous patent.

The mechanism for imparting motion to the drill through the adjustable support and past the face of the cutter I consists of an arm or chuck, K, adapted to engage with the drill to be cleared and move it through the adjustable support B and past the face of the clearing-tool I without interfering with the revolution of the drill. Motion is imparted to this part K by means of a rod, L, which it is slotted to receive, and on which its position may be adjusted. This rod L'slides in suitable supports, M, attached to the main frame of the machine. This rod L may be slid within its supports either by means of the crosshandle N, attached to it and sliding upon the main frame A of the machine, or by means of the screw 0 and crank 0, also attached to the main frame of the machine by standards I, and passing through an interiorly-threaded arm or strap, R, attached to the said rod L. This arm or strap R forms in substance a nut firmly attached to or connected with the rod L, and driven by the screw 0, when the latter revolves.

It will be observed with regard to the operation of the mechanism just described that it differs from that shown in my previous patent, among other respects, in thisviz., that in my present machine the power which moves the drill by the cutter is preferably applied to the point end of the drill instead of to the heel end, as in the other machine. This feature I find to be of value in working upon drills of small cross-section.

Rotary motion is given to the drill as it is moved through the support B and past the cutter I by means of a pin, 0, (shown in Figs. 3 to 6,) which enters the spiral groove of the moving drill and causes it to rotate as it passes along. The mounting of the pin 0 in the support B is likewise an improvement over my machine as formerly patented, by reason of its reducing the number of parts and simp1ifying the structure generally.

The operation of the machine is as follows: The rod L and its attached chuck K having been advanced sufficiently beyond the jaws B, the latter are opened and the drill is placed within the jaws, which seize and support it at its butt, leaving that portion of the drill to be cleared outside or beyond the jaws, as shown in Fig. 1. The drill having been put in place within the jaws B, and its point being supported by the chuck K, the clearing-tool I is brought up and adjusted in its place by means of the adjustments described. This clearingtool, being now set in motion by power applied to the pulley on the shaft E, grinds or clears away the cylindrical portions of the drill against which it acts; and while it continues to rotate the drill is gradually caused to pass-by the clearing-tool and through the support B by moving the rod L in the manner before described. The drill is also rotated at the same time by the pin 0 entering its groove. In this way the whole of the face of the drill to be cleared is gradually and successively moved before and eX- posed to the action of the clearing-tool I, and the clearing operation is performed.

In Figs. 3 to 6 I have illustrated a special construction of the jaw 13, whereby that portion of it which embraces and supports the drill to be cleared is formed separate from the main body of the jaw. I accomplish this, as shown in the drawings, by fitting into the main body of the lower jaw a cylindrical piece cut out in V shape, so as to receive and fit different sizes of drill, and cut off so as to be semi-cylindrical at one end where the finger or pin 0 passes through it. This construction enables me, by slightly rotating in either direction the cylinder (1, to adjust it, and with it the position of the fingers c relatively to the clearingtool I. I find this adjustment to be valuable in practice, because by means of it I am enabled to secure a more accurate and convenient adjustment of the drill relatively to the cutter; also, it is more readily replaced when worn or to accommodate difierent-sized drills.

1. In a machine for clearing twist-drills, supporting and guiding jaws adjustable for various sizes of drill, substantially as described.

2. I11 a machine for clearing twist-drills, the combination, with adjustable supporting and guiding jaws, of a sliding support for the point of the drill, all substantially as herein set forth.

3. In a machine for clearing twist-drills, the

combination, with mechanism for clearing the lands of the drill, of supporting-jaws adjustable for various sizes of drill, adapted to receive and support the drill, and mechanism for moving the drill longitudinally through the said jaws and past the said clearing mechanism, and also for rotating it during said longitudinal motion, all being substantially those herein shown and set forth, and for the purposes herein specified.

4. The combination, with mechanism of the character described for receiving and supporting drills of various sizes to be cleared, and provided with means, substantially the same as herein set forth, for regulating the vertical and lateral position of said mechanism, of a clearing-tool, I, provided with adjustments, substantially as herein described, whereby it may be adjusted toward and away from the drill and longitudinally upon the same, and also radially to correspond with the taper of the same, an arm or chuck for supporting the point of the said drill, said arm being adjustably mounted upon a rod, L, adapted to move the drill longitudinally past the cutter, and a finger or pin, 0, adapted to rotate the drill during such longitudinal motion, all substan tially as herein set forth. I

5. In combination, the adjustable chuck or i point-supporting arm K and sliding rodL, 25 when provided with suitable attachments, as set forth, for imparting longitudinal motion in both directions to the said arm and rod, substantially as herein described.

6. The combination of the adjustable point 0 supporting chuck K, sliding arm L, nutformed strap R, attached to said sliding rod, and screw 0, passing through the nut and entering said strap R, all substantially as set forth. 35

7. The improved adjustable drill-supporting jaw herein described, consisting of the main jaw B and cylindrical and supplemental jaw d, carrying the pin or finger c, all substantially as herein set forth, and for the pur- 4o poses herein specified.

In testimony whereof I have hereunto subscribed my name this 19th day of June,'A. D. 188a.

GEORGE R. STETSON.

XVitnesses:

HENRY B. WORTH, ELIOT D. STETsoN. 

